JP7107130B2 - storage module - Google Patents

Description

The present invention relates to an electric storage module.

Conventionally, as a power storage module, for example, as described in Japanese Patent Laid-Open No. 2005-5163, a plurality of bipolar electrodes are laminated to form a laminate, and the sides of the laminate are sealed with a resin. is known.

JP-A-2005-5163

In such an electric storage module, as shown in FIG. 7, the side portion of a laminate 102 in which bipolar electrodes 101 are laminated is sealed with a sealing body 103, and the end portion of the sealing body 103 is bent inward to form an overhang. It is conceivable to form a hang portion 103a. The overhang portion 103a extends inwardly of the laminated body 102, thereby suppressing the widening of the end portion of the laminated body 102. As shown in FIG. However, when the power storage module is used, the internal pressure of the power storage module may increase. In this case, as shown in FIG. 8, an internal pressure may be applied to the overhanging portion 103a of the sealing member 103, causing deformation.

Accordingly, an object of the present invention is to provide an electricity storage module capable of suppressing deformation of a sealing body that seals a laminate.

That is, an electricity storage module according to the present invention has a laminate in which a plurality of electrodes are laminated, and is configured by providing a sealing member on the side surface of the laminate. and an overhang part that bends and extends toward the inside of the laminate at the end of the main body part. thickly formed. According to this power storage module, the base end side of the overhang portion is formed thicker than the tip end side, so that the bending rigidity of the base end side of the overhang portion can be increased. Therefore, when the internal pressure of the laminate rises and bending stress is generated in the overhang, deformation of the overhang can be suppressed accurately. Further, by forming the base end side of the overhang portion thicker than the tip end side, it is possible to increase the bending rigidity of the overhang portion while suppressing an increase in the weight of the overhang portion.

Further, in the electric storage module according to the present invention, the overhang portion forms an inclined surface on the opposite side of the surface that contacts the laminate in the cross section of the laminate in the stacking direction, and the inclined surface is the base end of the overhang portion. You may incline so that thickness of a side may become large. In this case, by forming an inclined surface in the overhang, the thickness of the base end of the overhang can be increased, and the flexural rigidity of the overhang can be increased.

Moreover, in the electric storage module according to the present invention, the inclined surface may be inclined so that the bending stress of the overhang portion is constant. In this case, since the inclined surface is inclined so that the bending stress of the overhang is constant, the concentration of stress on a part of the overhang is suppressed when a load is applied from the laminate side. Therefore, the overhang portion can appropriately receive the load from the laminate side.

ADVANTAGE OF THE INVENTION According to this invention, the deformation|transformation of the sealing body which seals a laminated body can be suppressed.

1 is a schematic cross-sectional view of a power storage device using a power storage module according to an embodiment of the present invention; FIG. 1 is a schematic cross-sectional view showing an internal configuration of a power storage module according to an embodiment; FIG. FIG. 3 is a plan view of the power storage module of FIG. 2; FIG. 3 is an explanatory diagram of an overhang portion in the power storage module of FIG. 2; FIG. 3 is an explanatory diagram of an overhang portion in the power storage module of FIG. 2; 3 is an explanatory diagram of a modified example of an overhang portion in the power storage module of FIG. 2; FIG. It is an explanatory view of background art. It is an explanatory view of background art.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals, and redundant explanations are omitted.

FIG. 1 is a schematic cross-sectional view of a power storage device 1 using power storage modules 4 according to this embodiment. A power storage device 1 shown in FIG. 1 shows an example of a power storage device using a power storage module 4, and is used as a battery for various vehicles such as forklifts, hybrid vehicles, and electric vehicles, for example. The power storage device 1 includes a module stack 2 including a plurality of stacked power storage modules 4, and is restrained in the stacking direction of the module stack 2 (here, the stacking direction D of the electrodes in the electrode stack 11 to be described later). and a restraining member 3 for applying a load.

The module laminate 2 includes a plurality of (here, three) power storage modules 4 and a plurality of (here, four) conductive plates 5 . The power storage module 4 is a bipolar battery and has a rectangular shape when viewed from the stacking direction D. As shown in FIG. The storage module 4 is, for example, a secondary battery such as a nickel-hydrogen secondary battery or a lithium-ion secondary battery, or an electric double layer capacitor. In the following description, a nickel-metal hydride secondary battery is exemplified.

Electricity storage modules 4 adjacent to each other in the stacking direction D are electrically connected via conductive plates 5 . The conductive plates 5 are arranged between the power storage modules 4 adjacent to each other in the stacking direction D and outside the power storage module 4 positioned at the stack end in the stacking direction D, respectively. A positive electrode terminal 6 is connected to one of the conductive plates 5 arranged outside in the stacking direction D of the storage module 4 positioned at the end of the stack. A negative electrode terminal 7 is connected to the other conductive plate 5 arranged outside in the stacking direction D of the storage module 4 positioned at the end of the stack. The positive terminal 6 and the negative terminal 7 are pulled out in a direction crossing the stacking direction D, for example, from the edge of the conductive plate 5 . The power storage device 1 is charged and discharged by the positive terminal 6 and the negative terminal 7 .

Inside the conductive plate 5, a plurality of flow paths 5a for circulating a coolant such as air are provided. The channel 5a extends along a direction that intersects (perpendicularly) the stacking direction D and the drawing direction of the positive electrode terminal 6 and the negative electrode terminal 7, for example. The conductive plate 5 functions not only as a connecting member that electrically connects the storage modules 4, but also as a radiator plate that dissipates the heat generated in the storage modules 4 by circulating the coolant through the flow paths 5a. Combine functions. In the example of FIG. 1, the area of the conductive plate 5 when viewed from the stacking direction D is smaller than the area of the storage module 4, but from the viewpoint of improving heat dissipation, the area of the conductive plate 5 is smaller than that of the storage module 4. It may be the same as the area, or may be larger than the area of the power storage module 4 .

The restraining member 3 includes a pair of end plates 8 sandwiching the module stack 2 in the stacking direction D, and fastening bolts 9 and nuts 10 fastening the end plates 8 together. The end plate 8 is a rectangular metal plate having an area slightly larger than the area of the storage module 4 and the conductive plate 5 when viewed in the stacking direction D. As shown in FIG. An electrically insulating film F is provided on the inner surface of the end plate 8 in the stacking direction D (the surface facing the module stack 2 side). The film F insulates between the end plate 8 and the conductive plate 5 .

The end plate 8 is provided with an insertion hole 8a at an edge portion on the outer peripheral side of the portion overlapping the module stack 2 in the stacking direction D. As shown in FIG. The fastening bolt 9 is passed from the insertion hole 8a of one end plate 8 toward the insertion hole 8a of the other end plate 8, and the tip portion of the fastening bolt 9 protruding from the insertion hole 8a of the other end plate 8 has a , a nut 10 is screwed. As a result, the energy storage module 4 and the conductive plate 5 are sandwiched between the end plates 8 to form a module laminate 2 as a unit, and a binding load is applied to the module laminate 2 in the stacking direction D. As shown in FIG.

Next, the configuration of the power storage module 4 will be described in detail. FIG. 2 is a schematic cross-sectional view showing the internal configuration of power storage module 4 shown in FIG. As shown in FIG. 2 , the power storage module 4 has an electrode laminate (laminate) 11 in which a plurality of electrodes are laminated, and is configured by providing a sealing body 12 on the outer edge of the electrode laminate 11 . . The electrode laminate 11 includes a separator 13, and a plurality of electrodes (a plurality of bipolar electrodes 14, a single negative terminal electrode 18, and a single positive terminal electrode 19) laminated along the stacking direction D via the separator 13. including. Here, the stacking direction D of the electrode stack 11 coincides with the stacking direction of the module stack 2 . The electrode laminate 11 has a side surface 11b extending in the lamination direction D. As shown in FIG.

Bipolar electrode 14 includes electrode plate 15 , positive electrode 16 and negative electrode 17 . The positive electrode 16 is provided on the first surface 15 a of the electrode plate 15 . The negative electrode 17 is provided on the second surface 15b of the electrode plate 15 opposite to the first surface 15a. The electrode plate 15 is made of metal such as nickel or nickel-plated steel plate, for example. As an example, the electrode plate 15 is a rectangular metal foil made of nickel. The electrode plate 15 includes a rectangular outer edge 15d when viewed in the stacking direction D. As shown in FIG.

The positive electrode 16 is a positive electrode active material layer formed by coating the electrode plate 15 with a positive electrode active material. Examples of the positive electrode active material forming the positive electrode 16 include nickel hydroxide. The positive electrode 16 includes a rectangular outer edge when viewed in the stacking direction D. As shown in FIG. The negative electrode 17 is a negative electrode active material layer formed by coating the electrode plate 15 with a negative electrode active material. Examples of negative electrode active materials that constitute the negative electrode 17 include hydrogen storage alloys. The negative electrode 17 includes a rectangular outer edge when viewed in the stacking direction D. As shown in FIG.

In this embodiment, for example, the formation area of the negative electrode 17 on the second surface 15 b of the electrode plate 15 is larger than the formation area of the positive electrode 16 on the first surface 15 a of the electrode plate 15 . That is, the outer edge of the negative electrode 17 is one size larger than the outer edge of the positive electrode 16 . A peripheral portion of the electrode plate 15 has a rectangular frame shape and is an uncoated region where the positive electrode active material and the negative electrode active material are not coated. In other words, the peripheral portion of the electrode plate 15 is a portion of the electrode plate 15 other than the region where the positive electrode 16 and the negative electrode 17 are formed and surrounds the positive electrode 16 and the negative electrode 17 when viewed from the stacking direction D. The surfaces of the bipolar electrode 14 , the negative terminal electrode 18 , and the positive terminal electrode 19 respectively include the first surface 15 a and the second surface 15 b of the peripheral portion of the electrode plate 15 .

In the electrode stack 11 , the positive electrode 16 of one bipolar electrode 14 faces the negative electrode 17 of another bipolar electrode 14 adjacent in the stacking direction D with the separator 13 interposed therebetween. In the electrode stack 11 , the negative electrode 17 of one bipolar electrode 14 faces the positive electrode 16 of another bipolar electrode 14 adjacent in the stacking direction D with the separator 13 interposed therebetween.

The negative terminal electrode 18 includes the electrode plate 15 and the negative electrode 17 provided on the second surface 15 b of the electrode plate 15 . Negative terminal electrode 18 does not include positive electrode 16 . That is, no active material layer is provided on the first surface 15a of the electrode plate 15 of the negative terminal electrode 18 (that is, the entire first surface 15a of the negative terminal electrode 18 is exposed). The negative terminal electrode 18 is arranged at one end in the stacking direction D so that the second surface 15b faces the inside of the stacking direction D of the electrode stack 11 (the center side with respect to the stacking direction D). The negative electrode 17 of the negative terminal electrode 18 faces the positive electrode 16 of the bipolar electrode 14 at one end in the stacking direction D with the separator 13 interposed therebetween.

The positive terminal electrode 19 includes the electrode plate 15 and the positive electrode 16 provided on the first surface 15 a of the electrode plate 15 . Positive terminal electrode 19 does not include negative electrode 17 . That is, no active material layer is provided on the second surface 15b of the electrode plate 15 of the positive terminal electrode 19 (that is, the entire second surface 15b of the positive terminal electrode 19 is exposed). The positive terminal electrode 19 is arranged at the other end in the stacking direction D such that the first surface 15 a faces the inside of the stacking direction D of the electrode stack 11 . The positive electrode 16 of the positive terminal electrode 19 faces the negative electrode 17 of the bipolar electrode 14 at the other end in the stacking direction D with the separator 13 interposed therebetween.

The conductive plate 5 is in contact with the first surface 15 a of the electrode plate 15 of the negative terminal electrode 18 . Also, the second surface 15b of the electrode plate 15 of the positive terminal electrode 19 is in contact with the conductive plate 5 of the adjacent electricity storage module 4 . A binding load from the binding member 3 is applied to the electrode laminate 11 from the negative terminal electrode 18 and the positive terminal electrode 19 via the conductive plate 5 . That is, the conductive plate 5 is also a restraining member that applies a restraining load to the electrode laminate 11 along the lamination direction D. As shown in FIG.

The separator 13 is formed in a sheet shape, for example. Examples of the separator 13 include porous films made of polyolefin resins such as polyethylene (PE) and polypropylene (PP), and woven or nonwoven fabrics made of polypropylene, methyl cellulose, and the like. The separator 13 may be reinforced with a vinylidene fluoride resin compound. Note that the separator 13 is not limited to a sheet shape, and may be bag-shaped.

An intermediate resin portion 23 is provided in the bipolar electrode 14 . The intermediate resin portion 23 functions as a primary seal that seals between the bipolar electrodes 14 , 14 . The intermediate resin portion 23 is provided along the outer edge of the bipolar electrode 14 and is provided over the entire circumference of the bipolar electrode 14 . The intermediate resin portion 23 is provided so as to be joined to the outer edge of the electrode plate 15 . An end portion of the intermediate resin portion 23 is joined to the sealing body 12 . That is, the bipolar electrode 14 is joined to the sealing body 12 via the intermediate resin portion 23 and supported by the sealing body 12 . The intermediate resin portion 23 includes, for example, a first intermediate resin portion 231 and a second intermediate resin portion 232 . In some cases, the intermediate resin portion 23 is composed of a single member.

A negative terminal resin portion 24 is provided on the negative terminal electrode 18 . The negative terminal resin portion 24 is a member provided at the end of the electrode laminate 11 in the stacking direction D, and functions as a primary seal that seals the end of the electrode laminate 11 . The negative terminal resin part 24 is formed, for example, in the shape of a rectangular frame, and is welded to the surface of the negative terminal electrode 18 . The negative terminal electrode 18 is an electrode arranged at the end of the electrode laminate 11 and is composed of the electrode plate 15 and the negative electrode 17 .

A positive terminal resin portion 26 is provided on the positive terminal electrode 19 . The positive electrode termination resin portion 26 is a member provided at the end of the electrode laminate 11 in the stacking direction D, and functions as a primary seal that seals the end of the electrode laminate 11 . The positive terminal resin part 26 is formed, for example, in a rectangular frame shape and welded to the surface of the positive terminal electrode 19 . The positive terminal electrode 19 is an electrode arranged at the end of the electrode laminate 11 and is composed of the electrode plate 15 and the positive electrode 16 .

The sealing body 12 is provided along the outer edge of the electrode laminate 11 . The sealing body 12 is formed in a rectangular frame shape and functions as a secondary seal for sealing the side surface 11 b of the electrode laminate 11 . The sealing body 12 includes a main body portion 12a and an overhang portion 12b, and is made of an insulating resin, for example. The body portion 12 a is formed to cover the side surface 11 b of the electrode laminate 11 . For example, the body portion 12 a covers the side surface 11 b of the electrode laminate 11 over the entire circumference. The overhang portion 12b bends and extends toward the inside of the electrode laminate 11 at the end portion of the main body portion 12a. The overhang portions 12b are formed at both ends of the body portion 12a, respectively, and suppress expansion of the electrode laminate 11 in the lamination direction D. As shown in FIG.

Between the bipolar electrodes 14 adjacent to each other along the stacking direction D, between the negative terminal electrode 18 and the bipolar electrode 14 adjacent to each other along the stacking direction D, and along the stacking direction D It seals between the positive terminal electrode 19 and the bipolar electrode 14 adjacent to each other. As a result, airtight (liquid-tight) internal spaces V are provided between the bipolar electrodes 14, between the negative electrode terminal electrode 18 and the bipolar electrode 14, and between the positive electrode terminal electrode 19 and the bipolar electrode 14, respectively. is formed. The internal space V accommodates an electrolytic solution (not shown) composed of an alkaline aqueous solution such as an aqueous potassium hydroxide solution. That is, the first resin portion 21 forms an internal space V in which the electrolytic solution is accommodated between the electrodes adjacent in the stacking direction D, and seals the internal space V. As shown in FIG. The electrolytic solution is impregnated in the separator 13 , the positive electrode 16 and the negative electrode 17 .

The sealing body 12 is, for example, an insulating resin and can be made of polypropylene (PP), polyphenylene sulfide (PPS), modified polyphenylene ether (modified PPE), or the like.

FIG. 3 is a plan view of the power storage module 4 when viewed from the stacking direction D. FIG. As shown in FIG. 3 , the power storage module 4 is configured by providing a sealing body 12 on the outer edge of a rectangular electrode laminate 11 . The electrode stack 11 is provided by stacking a plurality of bipolar electrodes 14, and has a rectangular cross section in a direction orthogonal to the stacking direction of the bipolar electrodes 14. As shown in FIG. The sealing body 12 is continuously provided on the outer edge of the electrode laminate 11 over the entire circumference. That is, the sealing body 12 is provided continuously over the entire circumference of the outer edge of the electrode laminate 11 when the electrode laminate 11 is viewed from the stacking direction, and has a rectangular frame shape.

FIG. 4 shows a sectional view of the overhang portion 12b. FIG. 4 shows a cross section of the overhang portion 12b in the stacking direction D of the electrode stack 11. As shown in FIG. The overhang portion 12b bends and extends toward the inside of the electrode laminate 11 at the end portion of the main body portion 12a. Here, the inner side of the electrode laminate 11 means the center side of the electric storage module 4 when viewed from the stacking direction D. As shown in FIG. On the other hand, the outer side of the electrode laminate 11 means the side away from the center of the power storage module 4 when viewed from the stacking direction D. As shown in FIG. The maximum height of the overhang portion 12b is set to be equal to or less than the height of the conductive plate 5. As shown in FIG. That is, the maximum height of the overhang portion 12b in the stacking direction D is equal to or less than the height of the conductive plate 5 . This prevents the overhang portion 12 b from contacting a part of the adjacent power storage module 4 .

The overhang portion 12b is formed thicker on the base end side than on the tip end side in the cross section of the electrode laminate 11 in the stacking direction D. As shown in FIG. That is, the thickness of the overhang portion 12b on the base end side is larger than the thickness on the tip end side. The base end side of the overhang portion 12b means the side closer to the body portion 12a, and the tip end side of the overhang portion 12b means the side farther from the body portion 12a. In other words, the overhang portion 12b is formed so as to taper on the tip side.

For example, the overhang portion 12 b forms an inclined surface 12 c on the opposite side of the surface that contacts the electrode laminate 11 in the cross section of the electrode laminate 11 in the stacking direction D. As shown in FIG. The inclined surface 12c is inclined so that the thickness of the base end side of the overhang portion 12b is increased. That is, the inclined surface 12 c is inclined toward the inside of the electrode laminate 11 so as to approach the electrode laminate 11 . Although FIG. 4 shows only one of the overhangs 12b at both ends of the main body 12a, the other overhang 12b is also provided in the same manner.

The inclination angle of the inclined surface 12c may be set according to the bending stress generated in the overhang portion 12b. For example, the inclined surface 12c may be inclined so that the bending stress of the overhang portion 12b is constant. That is, the inclined surface 12c may be formed so that the overhang portion 12b functions as a so-called uniform strength beam. As shown in FIG. 5, when the internal pressure of the power storage module 4 increases, the overhang portion 12b receives a load P from the electrode laminate 11 side. At this time, a bending stress S is generated in the overhang portion 12b by receiving the load P. The inclined surface 12c is formed so that the bending stress S is constant at each location from the base end to the tip end. It should be noted that the term "constant bending stress" as used herein includes the case where the bending stress is substantially constant. In this way, by forming the inclined surface 12c so that the bending stress S generated in the overhang portion 12b is constant, it is possible to suppress the concentration of stress on a part of the overhang portion 12b. Therefore, the overhang portion 12b can appropriately receive the load P from the laminate side. In addition, the inclined surface 12c may be formed in a planar shape, or may be formed in a curved shape as shown in FIG.

Next, the deformation suppressing function of the storage module 4 according to this embodiment will be described.

In FIG. 2, when the power storage module 4 is used as a battery, the internal pressure of the power storage module 4 may increase. That is, the internal pressure of the electrode laminate 11 may increase, and a load may be applied to the sealing body 12 . In this case, the load in the stacking direction D is applied from the electrode stack 11 side to the overhang portion 12b of the sealing body 12 .

At this time, the sealing body 12 is required to receive the load without being deformed as much as possible. Therefore, in the power storage module 4 according to the present embodiment, the base end side of the overhang portion 12b is formed thicker than the tip end side. That is, as shown in FIG. 4, in the cross section of the electrode laminate 11 in the stacking direction D, the thickness of the overhang portion 12b in the stacking direction D is formed thicker on the base end side than on the tip end side. Therefore, it is possible to increase the bending rigidity on the base end side of the overhang portion 12b where stress is likely to concentrate. Thereby, as shown in FIG. 5, even when the load P is applied to the overhang portion 12b, the deformation of the overhang portion 12b can be suppressed accurately.

Further, by forming the base end side of the overhang portion 12b thicker than the tip end side, it is possible to increase the bending rigidity of the overhang portion 12b while suppressing an increase in the weight of the overhang portion 12b. Moreover, the bending rigidity of the overhang portion 12b can be increased while suppressing the overhang portion 12b from becoming large. Therefore, when a plurality of power storage modules 4 are stacked in the stacking direction D, interference such as contact between the overhang parts 12b of the vertically adjacent power storage modules 4 can be avoided, and the bending rigidity of the overhang parts 12b can be increased. can be increased.

In addition, the overhang portion 12b has an inclined surface 12c on the side opposite to the surface in contact with the electrode laminate 11 in the cross section of the electrode laminate 11 in the lamination direction D, and the inclined surface 12c is the overhang portion 12b. It is inclined so that the thickness on the proximal side increases. Therefore, by forming such an inclined surface 12c, it is possible to increase the thickness of the base end side of the overhang portion 12b and increase the bending rigidity of the overhang portion 12b.

Further, as shown in FIG. 5, the inclined surface 12c is inclined so that the bending stress of the overhang portion 12b is constant. When the internal pressure of the power storage module 4 increases, the overhang portion 12b receives the load P from the electrode laminate 11 side. In this case, since the inclined surface 12c is inclined so that the bending stress S generated in the overhang portion 12b is constant, concentration of stress on a part of the overhang portion 12b is suppressed. Therefore, the bending rigidity of the overhang portion 12b with respect to the load P is increased, and deformation of the overhang portion 12b can be suppressed even if a strong load P is received.

As described above, according to the power storage module 4 according to the present embodiment, the base end side of the overhang portion 12b is formed thicker than the tip end side, thereby increasing the bending rigidity of the base end side of the overhang portion 12b. be able to. Therefore, when the internal pressure of the electrode laminate 11 rises and bending stress is generated in the overhang portion 12b, deformation of the overhang portion 12b can be suppressed accurately. Further, by forming the base end side of the overhang portion 12b thicker than the tip end side, it is possible to increase the bending rigidity of the overhang portion 12b while suppressing an increase in the weight of the overhang portion 12b.

In addition, in the storage module 4 according to the present embodiment, by forming the inclined surface 12c in the overhang portion 12b, the thickness of the base end side of the overhang portion 12b can be increased, and the bending rigidity of the overhang portion 12b can be increased. can increase

In addition, in the storage module 4 according to the present embodiment, by forming the inclined surface 12c so that the bending stress of the overhang portion 12b is constant, the overhang portion 12b receives the load P from the electrode laminate 11 side. In this case, concentration of stress on a portion of the overhang portion 12b is suppressed. Therefore, the overhang portion 12b can appropriately receive the load P from the electrode laminate 11 side.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment.

For example, in the above-described embodiment, the case of using the power storage device 1 in which the power storage modules 4 are stacked as shown in FIG. 1 has been described, but the power storage modules 4 may be used in a different structure or form. Moreover, in the above-described embodiment, the case where the power storage module 4 is used as a battery for various vehicles such as a forklift, a hybrid vehicle, and an electric vehicle has been described, but it may be used for other purposes.

4 power storage module 11 electrode laminate (laminate) 12 sealing body 12a body portion 12b overhang portion 12c inclined surface 14 bipolar electrode 15 electrode plate 15a third 1st surface 15b Second surface 16 Positive electrode 17 Negative electrode 18 Negative terminal electrode 23 Intermediate resin part 24 Negative terminal resin part D Lamination direction P Load S Bending stress.

Claims (2)

In an electricity storage module having a laminate in which a plurality of electrodes are laminated, and a sealing body provided on a side surface of the laminate,
The sealing body includes a main body covering the side surface of the laminate, and an overhang extending at an end of the main body to the inside of the laminate,
The base end side of the overhang portion is formed thicker than the tip end side in the cross section of the laminate in the stacking direction,
The overhang portion forms an inclined surface on the side opposite to the surface in contact with the laminate in the cross section of the laminate in the stacking direction,
The slanted surface is slanted so that the thickness of the base end of the overhang is increased and the bending stress of the overhang is constant.
storage module. In an electricity storage module having a laminate in which a plurality of electrodes are laminated, and a sealing body provided on a side surface of the laminate,
The sealing body includes a main body extending in the lamination direction of the laminate and covering side surfaces of the laminate, and overhangs extending inwardly of the laminate at both ends of the main body. ,
The base end side of the overhang portion is formed thicker than the tip end side in the cross section of the laminate in the stacking direction,
The overhang portion forms an inclined surface on the side opposite to the surface in contact with the laminate in the cross section of the laminate in the stacking direction,
The inclined surface is inclined so that the thickness of the base end side of the overhang portion increases, and is formed from the position of the base end of the overhang portion to the position of the tip end,
The laminate has a frame-shaped negative electrode termination resin portion arranged at one end in the stacking direction, and a frame-shaped positive electrode termination resin portion arranged at the other end in the stacking direction. ,
The negative terminal resin part is welded to the negative terminal electrode,
The positive terminal resin part is welded to the positive terminal electrode,
the overhang portion is in contact with the negative electrode termination resin portion and the positive electrode termination resin portion, respectively;
When viewed from the stacking direction, the tip of the overhang portion is located outside the laminate from the inner edge of the negative electrode terminal resin portion and the inner edge of the positive electrode terminal resin portion.
storage module.

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